The use of paddles and oars to propel boats goes back to the pre-history era of mankind. A wide variety of devices for doing so have been devised.
Some prior art rowing arrangements have utilized a plurality of paddles which are simultaneously actuated by a person rowing. Such devices are normally a physical part of the boat structure; that is, the rowing systems are positively connected to or an integral part of the boat.
The following patent documents are believed to be representative of the current state of the prior art in this field: U.S. Pat. No. 7,520,788, issued Apr. 21, 2009, U.S. Pat. No. 7,922,549, issued Apr. 12, 2011, U.S. Pat. No. 5,041,037, issued Aug. 20, 1991, U.S. Pat. No. 4,098,219, issued Jul. 4, 1978, U.S. Pat. No. 4,002,137, issued Jan. 11, 1977, U.S. Pat. No. 3,967,574, issued Jul. 6, 1976, U.S. Pat. No. 3,677,216, issued Jul. 18, 1972, U.S. Pat. No. 528,702, issued Nov. 6, 1894, U.S. Patent Application Pub. No. US 2016/0244136, published Aug. 25, 2016, U.S. Patent Application Pub. No. US 2016/0096605, published Apr. 7, 2016 and British Patent No. 313,815, issued Jun. 20, 1929.